An In Situ TEM Study of the Influence of Water Vapor on Reduction of Nickel Phyllosilicate - Retarded Growth of Metal Nanoparticles at Higher Rates.

Unavoidable water formation during the reduction of solid catalyst precursors has long been known to influence the nanoparticle size and dispersion in the active catalyst. This in situ transmission electron microscopy study provides insight into the influence of water vapor at the nanoscale on the nucleation and growth of the nanoparticles (2-16 nm) during the reduction of a nickel phyllosilicate catalyst precursor under H2/Ar gas at 700 °C. Water suppresses and delays nucleation, but counterintuitively increases the rate of particle growth. After full reduction is achieved, water vapor significantly enhances Ostwald ripening which in turn increases the likelihood of particle coalescence. This study proposes that water leads to formation of mobile nickel hydroxide species, leading to faster rates of particle growth during and after reduction.

Signal regulatory protein beta 2 is a novel positive regulator of innate anticancer immunity.

In recent years, the therapeutic (re)activation of innate anticancer immunity has gained prominence, with therapeutic blocking of the interaction of Signal Regulatory Protein (SIRP)-α with its ligand CD47 yielding complete responses in refractory and relapsed B cell lymphoma patients. SIRP-α has as crucial inhibitory role on phagocytes, with e.g., its aberrant activation enabling the escape of cancer cells from immune surveillance. SIRP-α belongs to a family of paired receptors comprised of not only immune-inhibitory, but also putative immune-stimulatory receptors. Here, we report that an as yet uninvestigated SIRP family member, SIRP-beta 2 (SIRP-ß2), is strongly expressed under normal physiological conditions in macrophages and granulocytes at protein level. Endogenous expression of SIRP-ß2 on granulocytes correlated with trogocytosis of cancer cells. Further, ectopic expression of SIRP-ß2 stimulated macrophage adhesion, differentiation and cancer cell phagocytosis as well as potentiated macrophage-mediated activation of T cell Receptor-specific T cell activation. SIRP-ß2 recruited the immune activating adaptor protein DAP12 to positively regulate innate immunity, with the charged lysine 202 of SIRP-ß2 being responsible for interaction with DAP12. Mutation of lysine 202 to leucine lead to a complete loss of the increased adhesion and phagocytosis. In conclusion, SIRP-ß2 is a novel positive regulator of innate anticancer immunity and a potential costimulatory target for innate immunotherapy.

Direct Observation of Ni Nanoparticle Growth in Carbon-Supported Nickel under Carbon Dioxide Hydrogenation Atmosphere.

Understanding nanoparticle growth is crucial to increase the lifetime of supported metal catalysts. In this study, we employ in situ gas-phase transmission electron microscopy to visualize the movement and growth of ensembles of tens of nickel nanoparticles supported on carbon for CO2 hydrogenation at atmospheric pressure (H2:CO2 = 4:1) and relevant temperature (450 °C) in real time. We observe two modes of particle movement with an order of magnitude difference in velocity: fast, intermittent movement (vmax = 0.7 nm s-1) and slow, gradual movement (vaverage = 0.05 nm s-1). We visualize the two distinct particle growth mechanisms: diffusion and coalescence, and Ostwald ripening. The diffusion and coalescence mechanism dominates at small interparticle distances, whereas Ostwald ripening is driven by differences in particle size. Strikingly, we demonstrate an interplay between the two mechanisms, where first coalescence takes place, followed by fast Ostwald ripening due to the increased difference in particle size. Our direct visualization of the complex nanoparticle growth mechanisms highlights the relevance of studying nanoparticle growth in supported nanoparticle ensembles under reaction conditions and contributes to the fundamental understanding of the stability in supported metal catalysts.

Galectin-9 has non-apoptotic cytotoxic activity toward acute myeloid leukemia independent of cytarabine resistance.

Acute myeloid leukemia (AML) is a malignancy still associated with poor survival rates, among others, due to frequent occurrence of therapy-resistant relapse after standard-of-care treatment with cytarabine (AraC). AraC triggers apoptotic cell death, a type of cell death to which AML cells often become resistant. Therefore, therapeutic options that trigger an alternate type of cell death are of particular interest. We previously identified that the glycan-binding protein Galectin-9 (Gal-9) has tumor-selective and non-apoptotic cytotoxicity towards various types of cancer, which depended on autophagy inhibition. Thus, Gal-9 could be of therapeutic interest for (AraC-resistant) AML. In the current study, treatment with Gal-9 was cytotoxic for AML cells, including for CD34+ patient-derived AML stem cells, but not for healthy cord blood-derived CD34+ stem cells. This Gal-9-mediated cytotoxicity did not rely on apoptosis but was negatively associated with autophagic flux. Importantly, both AraC-sensitive and -resistant AML cell lines, as well as AML patient samples, were sensitive to single-agent treatment with Gal-9. Additionally, Gal-9 potentiated the cytotoxic effect of DNA demethylase inhibitor Azacytidine (Aza), a drug that is clinically used for patients that are not eligible for intensive AraC treatment. Thus, Gal-9 is a potential therapeutic agent for the treatment of AML, including AraC-resistant AML, by inducing caspase-independent cell death.

Efficacy of customized corneal crosslinking versus standard corneal crosslinking in patients with progressive keratoconus (C-CROSS study): study protocol for a randomized controlled trial.

BACKGROUND: Keratoconus is a degenerative disorder of the cornea leading to a protrusion and thinning with loss of visual acuity. The only treatment to halt the progression is corneal crosslinking (CXL), which uses riboflavin and UV-A light to stiffen the cornea. Recent ultra-structural examinations show that the disease is regional and does not affect the entire cornea. Treating only the affected zone with CXL could be as good as the standard CXL, that treats the entire cornea. METHODS: We set up a multicentre non-inferiority randomized controlled clinical trial comparing standard CXL (sCXL) and customized CXL (cCXL). Patients between 16 and 45 years old with progressive keratoconus were included. Progression is based on one or more of the following changes within 12 months: 1 dioptre (D) increase in keratometry (Kmax, K1, K2); or 10% decrease of corneal thickness; or 1 D increase in myopia or refractive astigmatism, requiring corneal crosslinking. DISCUSSION: The goal of this study is to evaluate whether the effectiveness of cCXL is non-inferior to sCXL in terms of flattening of the cornea and halting keratoconus progression. Treating only the affected zone could be beneficial for minimalizing the risk of damaging surrounding tissues and faster wound healing. Recent non-randomized studies suggest that a customized crosslinking protocol based on the tomography of the patient's cornea may stop the progression of keratoconus and result in flattening of the cornea. TRIAL REGISTRATION: This study was prospectively registered at ClinicalTrials.gov on August 31st, 2020, the identifier of the study is NCT04532788.

M2 macrophages drive leukemic transformation by imposing resistance to phagocytosis and improving mitochondrial metabolism.

It is increasingly becoming clear that cancers are a symbiosis of diverse cell types and tumor clones. Combined single-cell RNA sequencing, flow cytometry, and immunohistochemistry studies of the innate immune compartment in the bone marrow of patients with acute myeloid leukemia (AML) reveal a shift toward a tumor-supportive M2-polarized macrophage landscape with an altered transcriptional program, with enhanced fatty acid oxidation and NAD+ generation. Functionally, these AML-associated macrophages display decreased phagocytic activity and intra-bone marrow coinjection of M2 macrophages together with leukemic blasts strongly enhances in vivo transformation potential. A 2-day in vitro exposure to M2 macrophages results in the accumulation of CALRlow leukemic blast cells, which are now protected against phagocytosis. Moreover, M2-exposed "trained" leukemic blasts display increased mitochondrial metabolism, in part mediated via mitochondrial transfer. Our study provides insight into the mechanisms by which the immune landscape contributes to aggressive leukemia development and provides alternatives for targeting strategies aimed at the tumor microenvironment.

Competition between reverse water gas shift reaction and methanol synthesis from CO2: influence of copper particle size.

Converting CO2 into value-added chemicals and fuels, such as methanol, is a promising approach to limit the environmental impact of human activities. Conventional methanol synthesis catalysts have shown limited efficiency and poor stability in a CO2/H2 mixture. To design improved catalysts, crucial for the effective utilization of CO2, an in-depth understanding of the active sites and reaction mechanism is desired. The catalytic performance of a series of carbon-supported Cu catalysts, with Cu particle sizes in the range of 5 to 20 nm, was evaluated under industrially relevant temperature and pressure, i.e. 260 °C and 40 bar(g). The CO2 hydrogenation reaction exhibited clear particle size effects up to 13 nm particles, with small nanoparticles having the lower activity, but higher methanol selectivity. MeOH and CO formation showed a different size-dependence. The TOFCO increased from 1.9 × 10-3 s-1 to 9.4 × 10-3 s-1 with Cu size increasing from 5 nm to 20 nm, while the TOFMeOH was size-independent (8.4 × 10-4 s-1 on average). The apparent activation energies for MeOH and CO formation were size-independent with values of 63 ± 7 kJ mol-1 and 118 ± 6 kJ mol-1, respectively. Hence the size dependence was ascribed to a decrease in the fraction of active sites suitable for CO formation with decreasing particle size. Theoretical models and DFT calculations showed that the origin of the particle size effect is most likely related to the differences in formate coverage for different Cu facets whose abundancy depends on particle size. Hence, the CO2 hydrogenation reaction is intrinsically sensitive to the Cu particle size.

Inhibition of Autophagy Does Not Re-Sensitize Acute Myeloid Leukemia Cells Resistant to Cytarabine.

Elevated activation of the autophagy pathway is currently thought to be one of the survival mechanisms allowing therapy-resistant cancer cells to escape elimination, including for cytarabine (AraC)-resistant acute myeloid leukemia (AML) patients. Consequently, the use of autophagy inhibitors such as chloroquine (CQ) is being explored for the re-sensitization of AraC-resistant cells. In our study, no difference in the activity of the autophagy pathway was detected when comparing AraC-Res AML cell lines to parental AraC-sensitive AML cell lines. Furthermore, treatment with autophagy inhibitors CQ, 3-Methyladenine (3-MA), and bafilomycin A1 (BafA1) did not re-sensitize AraC-Res AML cell lines to AraC treatment. However, in parental AraC-sensitive AML cells, treatment with AraC did activate autophagy and, correspondingly, combination of AraC with autophagy inhibitors strongly reduced cell viability. Notably, the combination of these drugs also yielded the highest level of cell death in a panel of patient-derived AML samples even though not being additive. Furthermore, there was no difference in the cytotoxic effect of autophagy inhibition during AraC treatment in matched de novo and relapse samples with differential sensitivity to AraC. Thus, inhibition of autophagy may improve AraC efficacy in AML patients, but does not seem warranted for the treatment of AML patients that have relapsed with AraC-resistant disease.

Cost analysis of mydriasis strategies in cataract surgery care in the Netherlands.

PURPOSE: To investigate the economic impact of an intracameral mydriatics and anesthetic agent (ICMA), topical mydriatics, and a mydriatic ocular insert in cataract patients. SETTING: One public hospital in the Netherlands. DESIGN: Prospective cohort study. METHODS: Resource use data were collected from a healthcare and societal perspective on the day of surgery. Other outcome parameters included pupil size, surgeon satisfaction, postoperative pain, and Catquest-9SF scores. RESULTS: A total of 368 patients were included, the mean costs per patient were €506 in the ICMA group (n = 122), €474 in the ocular insert group (n = 115), and €451 in the topical group (n = 131). The acquisition cost of ICMA was highest and resulted in longer surgical time. After correction for an imbalance in the distribution of fast and slow surgeons, the mean costs in the ocular insert and topical groups were comparable (€450 vs €444). There was no statistically significant difference in the use of additional mydriatics intraoperatively (P = .521). The mean ratio of pupil size to white-to-white distance was lower in the ICMA group during all intraoperative measurements (P < .001) but similar between the topical and ocular insert groups (P range .11-.82). CONCLUSIONS: In the investigated setting in the Netherlands, ICMA was the most costly strategy. In addition, pupil size was lowest in the ICMA group but did not result in more additional mydriasis measures intraoperatively. The ocular insert was comparable with topical mydriatics in costs and pupil size. Implementation of ICMA could be considered when availability of nurses or physical space for perioperative care is limited.

The Neutrophil: The Underdog That Packs a Punch in the Fight against Cancer.

The advent of immunotherapy has had a major impact on the outcome and overall survival in many types of cancer. Current immunotherapeutic strategies typically aim to (re)activate anticancer T cell immunity, although the targeting of macrophage-mediated anticancer innate immunity has also emerged in recent years. Neutrophils, although comprising ≈ 60% of all white blood cells in the circulation, are still largely overlooked in this respect. Nevertheless, neutrophils have evident anticancer activity and can induce phagocytosis, trogocytosis, as well as the direct cytotoxic elimination of cancer cells. Furthermore, therapeutic tumor-targeting monoclonal antibodies trigger anticancer immune responses through all innate Fc-receptor expressing cells, including neutrophils. Indeed, the depletion of neutrophils strongly reduced the efficacy of monoclonal antibody treatment and increased tumor progression in various preclinical studies. In addition, the infusion of neutrophils in murine cancer models reduced tumor progression. However, evidence on the anticancer effects of neutrophils is fragmentary and mostly obtained in in vitro assays or murine models with reports on anticancer neutrophil activity in humans lagging behind. In this review, we aim to give an overview of the available knowledge of anticancer activity by neutrophils. Furthermore, we will describe strategies being explored for the therapeutic activation of anticancer neutrophil activity.

Risk Factors for the Development of Ocular Hypertension After Keratoplasty: A Systematic Review.

PURPOSE: To identify risk factors for the development of ocular hypertension after keratoplasty. METHODS: A systematic search in PubMed and Embase identified 67 relevant articles published between January 1990 and 2019. We preferentially searched for data on an intraocular pressure increase above 21 mmHg at 6 months or a threshold or time point close to that and reported whether the preoperative or intraoperative status of risk factors was defined. The results were presented in evidence tables, visualizing the direction of the association, whether univariate and/or multivariate analysis was performed, and the significance level (P < 0.05). Four researchers, blinded for the risk factors, independently assigned a level of evidence (definitely, probably, possibly, not associated). Consensus was met during group meetings. RESULTS: From the 110 studied risk factors, pre-existing glaucoma, high preoperative IOP and combined keratoplasty with removal or exchange of an intraocular lens (IOL) were definitely associated with an increased risk. In addition, if the pre-or postoperative lens status was undefined, aphakia and pseudophakia with the IOL in the anterior or posterior chamber were also definitely associated with an increased risk when compared to phakia. Glaucoma in the contralateral eye, indication of bullous keratopathy, African American descent, preoperative treatment with cyclosporine or olopatadine 0.1%, postoperative treatment with prednisolone acetate 1%, and combined surgery in general (ie, the type of surgeries undefined in primary studies) were probably associated. Multiple other identified risk factors lack sufficient evidence and need additional investigation. CONCLUSIONS: Risk factors with a definite association can help clinicians select patients at risk and adjust their follow-up and treatment. The other factors need further investigation.

Trial-based cost-effectiveness analysis of toric versus monofocal intraocular lenses in cataract patients with bilateral corneal astigmatism in the Netherlands.

PURPOSE: To evaluate the cost-effectiveness of toric versus monofocal intraocular lens (IOL) implantation in cataract patients with bilateral corneal astigmatism. SETTING: Two ophthalmology clinics in the Netherlands. DESIGN: Prospective cost-effectiveness analysis. METHODS: Resource-use data were collected over a 6-month postoperative period. Consecutive patients with bilateral age-related cataract and 1.25 diopters or more of corneal astigmatism were included in the economic evaluation. Patients were randomized to phacoemulsification with bilateral toric or monofocal IOL implantation. All relevant resources were included in the cost analysis. The base-case analysis was performed from a societal perspective based on quality-adjusted life years (QALYs). The main outcome was the incremental cost-effectiveness ratio. RESULTS: The analysis comprised 77 consecutive patients (33 toric IOL; 44 monofocal IOL). Societal costs were higher in the toric IOL group (€3203 [$3864]) than in the monofocal IOL group (€2796 [US$3373]). QALYs were slightly lower in the toric IOL group (0.30 versus 0.31; P = .75). Toric IOLs were therefore inferior to monofocal IOLs from a cost-effectiveness perspective. The cost-effectiveness probability ranged from 1% to 15%, assuming a ceiling ratio for the incremental cost-effectiveness ratio of €2500 to €20 000 per QALY. CONCLUSIONS: From a societal perspective, bilateral toric IOL implantation in cataract patients with corneal astigmatism was not cost-effective compared with monofocal IOL implantation. Copayment by patients should therefore be considered.

Image-guided system versus manual marking for toric intraocular lens alignment in cataract surgery.

PURPOSE: To compare the accuracy of toric intraocular lens (IOL) alignment using the Verion Image-Guided System versus a conventional manual ink-marking procedure. SETTING: University Eye Clinic Maastricht, Maastricht, the Netherlands. DESIGN: Prospective randomized clinical trial. METHODS: Eyes with regular corneal astigmatism of at least 1.25 diopters (D) that required cataract surgery and toric IOL implantation (Acrysof SN6AT3-T9) were randomly assigned to the image-guided group or the manual-marking group. The primary outcome was the alignment of the toric IOL based on preoperative images and images taken immediately after surgery. Secondary outcome measures were residual astigmatism, uncorrected distance visual acuity (UDVA), and complications. RESULTS: The study enrolled 36 eyes (24 patients). The mean toric IOL misalignment was significantly less in the image-guided group than in the manual group 1 hour (1.3 degrees ± 1.6 [SD] versus 2.8 ± 1.8 degrees; P = .02) and 3 months (1.7 ± 1.5 degrees versus 3.1 ± 2.1 degrees; P < .05) postoperatively. The mean residual refractive cylinder was -0.36 ± 0.32 D and -0.47 ± 0.28 D in the image-guided group and manual group, respectively (P > .05). The mean UDVA was 0.03 ± 0.10 logarithm of minimum angle of resolution (logMAR) and 0.04 ± 0.09 logMAR, respectively (both P > .05). No intraoperative complications occurred during any surgery. CONCLUSION: The IOL misalignment was significantly less with digital marking than with manual marking; this did not result in a better UDVA or lower residual refractive astigmatism.

[Development and future prospects of cataract surgery]. / Ontwikkeling en toekomst van de cataractchirurgie.

In recent decades, enormous progress has been made in the development of intraocular lenses (IOLs) and cataract surgery. Before the development of the IOL, a cataract would cause impairment or loss of vision. Nowadays, cataract extractions are among the most frequently performed surgeries worldwide. The current cataract procedure is associated with a very low incidence of intra- and postoperative complications and satisfactory postoperative visual outcomes. Due to the increasing number of cataract surgeries performed annually, and an ageing population, development of IOLs and surgical techniques continues apace.

Toric vs aspherical control intraocular lenses in patients with cataract and corneal astigmatism: a randomized clinical trial.

IMPORTANCE: Spectacle independence is becoming increasingly important in cataract surgery. Not correcting corneal astigmatism at the time of cataract surgery will fail to achieve spectacle independency in 20% to 30% of patients. OBJECTIVE: To compare bilateral aspherical toric with bilateral aspherical control intraocular lens (IOL) implantation in patients with cataract and corneal astigmatism. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, hospital-based, randomized clinical trial was conducted. The participants included 86 individuals with bilateral cataract and bilateral corneal astigmatism of at least 1.25 diopters (D) who were randomized to receive either bilateral toric (n = 41) or bilateral control (n = 45) IOL implantation. INTERVENTIONS: Bilateral implantation of an aspherical toric IOL or an aspherical control IOL. MAIN OUTCOMES AND MEASURES: Spectacle independency for distance vision, uncorrected distance visual acuity, refractive astigmatism, contrast sensitivity, wavefront aberrations, and refractive error-related quality-of-life questionnaire. RESULTS: Preoperatively, mean (SD) corneal astigmatism was 2.02 (0.95) D and 2.00 (0.84) D in the toric and control groups, respectively. Four patients (5%) were lost to follow-up. At 6 months postoperatively, 26 (70%) of the patients in the toric group achieved an uncorrected distance visual acuity of 20/25 or better compared with 14 (31%) in the control group (P < .001; odds ratio, 5.23; 95% CI, 2.03-13.48). Spectacle independency for distance vision was achieved in 31 patients (84%) in the toric group compared with 14 patients (31%) in the control group (P < .001; odds ratio, 11.44; 95% CI, 3.89- 33.63). Mean refractive astigmatism was -0.77 (0.52) D and -1.89 D (1.00) D, respectively. Vector analysis of toric IOLs showed a mean magnitude of error of +0.38 D, indicative of overcorrection. No significant differences were found in contrast sensitivity, higher-order aberrations, or refractive error-related quality of life. CONCLUSIONS AND RELEVANCE: In patients with cataract and corneal astigmatism, bilateral toric IOL implantation results in a higher spectacle independency for distance vision compared with bilateral control IOL implantation. No significant differences were identified in contrast sensitivity, higher-order aberrations, or refractive error-related quality of life following both treatments. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01075542.

Visual acuity and refraction with a diffractive multifocal toric intraocular lens.

PURPOSE: To evaluate clinical outcomes and optical performance of the AT Lisa 909M diffractive multifocal toric intraocular lens (IOL). SETTING: Multicenter study. DESIGN: Cohort study. METHODS: The measured outcomes included refractive error; distance, near (40 cm), and intermediate (60 cm and 80 cm) visual acuities; defocus curve; rotational stability; and monocular and binocular photopic and mesopic contrast sensitivity. Astigmatism was evaluated by Alpins vector analysis. RESULTS: The multifocal toric IOL was implanted in 284 eyes of 142 patients. At 6 months, 89.4% of eyes were within ±1.00 diopter (D) of emmetropia. The mean refractive cylinder decreased from -2.39 D ± 1.48 (SD) to -0.49 ± 0.53 D; it was lower than 1.00 D in 80.9% of eyes. The mean visual acuities (logMAR) were monocular uncorrected distance 0.16 ± 0.22, monocular corrected distance 0.04 ± 0.15, binocular corrected distance -0.00 ± 0.09; monocular uncorrected near 0.21 ± 0.22, monocular corrected near 0.08 ± 0.16, binocular distance-corrected near 0.07 ± 0.14; intermediate at 60 cm (80 cm): monocular uncorrected 0.16 ± 0.21 (0.09 ± 0.21), monocular distance corrected 0.13 ± 0.19 (0.07 ± 0.20), and binocular distance corrected 0.07 ± 0.17 (0.00 ± 0.18). At 3 months and 6 months, 95.8% of IOLs showed no rotation over 5 degrees. CONCLUSIONS: This is the largest study yet on the first commercially available diffractive multifocal toric IOL. Results confirm its efficacy, predictability, and safety in restoring distance, near, and intermediate vision and allowing patients with significant levels of corneal astigmatism to achieve spectacle independence. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Toric intraocular lenses: historical overview, patient selection, IOL calculation, surgical techniques, clinical outcomes, and complications.

We present an overview of currently available toric intraocular lenses (IOLs) and multifocal toric IOLs. Relevant patient selection criteria, IOL calculation issues, and surgical techniques for IOL implantation are discussed. Clinical outcomes including uncorrected visual acuity, residual refractive astigmatism, and spectacle independency, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed. The incidence of misalignment, the most important complication of toric IOLs, is determined. Finally, future developments in the field of toric IOLs are discussed.

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies.

PURPOSE: To determine the comparability and repeatability of corneal astigmatism measurements obtained with different devices and determine the interobserver variability of a new automated keratometer. SETTING: University Eye Clinic Maastricht, the Netherlands. DESIGN: Prospective cohort study. METHODS: The right eye of healthy subjects was examined with the following 6 devices: IOLMaster (automated keratometry), Lenstar (automated keratometry), SMI Reference Unit 3 (automated keratometry), Javal (manual keratometry), KR-1W (corneal topography), and Pentacam (Scheimpflug imaging). An experienced operator obtained 3 repeated measurements. An inexperienced operator obtained additional measurements with the SMI Reference Unit 3. Astigmatism vector analysis was used to determine the comparability, repeatability, and interobserver variability. RESULTS: Corneal astigmatism vectors measured by automated, manual, or simulated keratometry were comparable except for the Pentacam equivalent keratometry (K) (P<.001, repeated-measures analysis of variance [ANOVA]). The mean difference between the equivalent K and other K values was 0.18 to 0.29 diopter (D) (P<.05, Hotelling trace multivariate ANOVA). The mean differences between automated, manual, and simulated keratometry were small (≤0.12 D). The within-subject standard deviation ranged from 0.05 D @ 21 degrees (KR-1W) to 0.18 D @ 23 degrees (Lenstar). The SMI Reference Unit showed small mean differences and comparable repeatability between the experienced operator and the inexperienced operator. CONCLUSIONS: Vector analysis showed comparable corneal astigmatism measurements using automated, manual, and simulated keratometry. Pentacam equivalent K values were not comparable with those of the other keratometers. The repeatability of astigmatism magnitudes was acceptable; however, the repeatability of astigmatism meridians was moderate. The SMI Reference Unit showed good interobserver variability.

Residual astigmatism following toric intraocular lens implantation related to pupil size.

PURPOSE: To present two patients with residual astigmatism following toric intraocular lens (IOL) implantation. METHODS: Case reports. RESULTS: A 58-year-old woman underwent toric IOL implantation (spherical power 29.50 diopters [D], cylinder power 3.00 D; SN60T5, Alcon Laboratories Inc) to correct 2.33 D @ 80° of corneal astigmatism. Postoperatively, uncorrected distance visual acuity (UDVA) was 20/30 and corrected distance visual acuity (CDVA) was 20/22 (0 -1.75 × 95), indicating an overcorrection of astigmatism. Slit-lamp examination demonstrated no IOL misalignment. Wavefront aberrometry showed a large pupil diameter (>6 mm) and a lower corneal astigmatism in a 6-mm zone (-1.40 D @ 174°) compared to a 4-mm zone (-2.21 D @ 171°). The second patient, a 60-year-old man, underwent multifocal toric IOL implantation (spherical power 22.50 D, cylinder power 2.25 D; SND1T4, Alcon Laboratories Inc) to correct 1.51 D @ 173° of corneal astigmatism. Postoperatively, UDVA was 20/50 and CDVA was 20/20 (+0.25 -1.00 × 102), indicating an undercorrection of astigmatism. Slit-lamp examination showed no misalignment. CONCLUSIONS: Both cases indicate that unexplained residual astigmatism following toric IOL implantation may be the result of multiple factors: the effect of the spherical power and anterior chamber depth on toric IOL calculations, the effect of posterior corneal astigmatism, and the effect of a large pupil size. The first two issues may be compensated for by improving toric IOL calculations. The latter indicates that pupillometry is indicated in relatively young patients who undergo toric IOL implantation.

Vector analysis of corneal and refractive astigmatism changes following toric pseudophakic and toric phakic IOL implantation.

PURPOSE: To determine the efficacy of the astigmatism correction following toric intraocular lens (IOL) and toric phakic IOL (pIOL) implantation in eyes with no previous ocular surgery and in postkeratoplasty (PKP) eyes. In addition, changes in corneal astigmatism were determined. METHODS: Astigmatism was analyzed in 35 eyes with an AcrySof toric IOL, 35 eyes with an Artiflex toric pIOL, 50 eyes with an Artisan toric pIOL, and 40 PKP eyes with an Artisan toric pIOL. Refractive astigmatism was analyzed by using Alpins method. Surgically induced corneal astigmatism (SICA) was determined following a superior 2.2-mm, 3.4-mm, or 5.4-mm incision. Follow-up was 12 months. RESULTS: Following toric IOL implantation, the index of success was 0.14 and overall residual astigmatism, 0.37 diopter (D). Following toric pIOL implantation, the index of success was 0.32 (Artiflex) and 0.18 (Artisan), and overall residual astigmatism was approximately 0.60 D. In PKP eyes, Artisan pIOLs resulted in an index of success of 0.28 and overall residual astigmatism of 1.56 D. The SICA, following 2.2-mm, 3.4-mm, 5.4-mm (normal eyes), and 5.4-mm (PKP eyes) incisions, was -0.25 ± 0.42 D (P = 0.108), -0.31 ± 0.43 D (P < 0.001), -0.48 ± 0.55 D (P < 0.001), and -0.49 ± 1.48 D (P = 0.035), respectively. CONCLUSIONS: Toric IOLs and pIOLs provide an effective astigmatism correction. Incorporating the SICA into the toric IOL power calculation may further increase their effectiveness. Therefore, incorporation of 0 D, -0.30 D, or -0.50 D of SICA for a 2.2-, 3.4-, or 5.4-mm superior incision, respectively, is recommended.